Michael Phelps revealed on Instagram that he and fiancee Nicole Johnson are expecting a baby boy.

The caption read: “We found out 8weeks ago we were expecting… Today we’re over 12 weeks and it looks like we’re having a boy!!! #babymp #mp #lifeabouttochange #mpswim @djnolan5”.

Nicole, the former Miss California, also shared the big news on her Instagram page, saying: “Today marks 12 weeks and 5 days of us having a little one and yesterday we learned we’re having a BOY We couldn’t be happier!! #babymp #mpswim @djnolan5”

The loved up pair, both 30, haven’t revealed when their wedding will take place, although Michael has said it won’t happen until after the Rio de Janiero Olympics in 2016.

Michael, who is the most decorated Olympian of all time, was suspended by USA Swimming for six months following his second DUI arrest but he proudly swam the fastest 200-metre butterfly this year.

The American athlete feels positive with his decision to check into an alcohol treatment facility and has since vowed not to drink, at least through the Rio Olympics.

“Haven’t had a single sip and will not have a sip,” he told Sports Illustrated in a recent interview. “My body fat has dropped significantly, and I’m leaner than I’ve ever been. The performances were there because I worked, recovered, slept and took care of myself more than I ever had.”